Mechanical fluid dispensers require the user to actuate the pumping mechanism by hand or foot. Operation by hand is not considered very sanitary and is undesirable for use in medical and dental facilities. The foot-actuated fluid dispenser is an unwieldly assembly which is cumbersome to use, bulky and expensive. Accordingly, a need exists for an inexpensive, compact and relatively small electronically-controlled fluid dispenser for universal clinical application in medical and dental facilities, as well as industrial and commercial institutions.
Electronically-controlled fluid dispensers are not new and to a limited degree are presently commercially available. The commercially available dispenser is an elaborate fluid pumping system containing a pump specifically designed for this purpose and a solenoid-controlled electromechanical assembly for operating the pump in response to an optically-detected signal. A solenoid consumes a substantial amount of power and accordingly must be powered by alternating current from a source of conventional AC power. The solenoid is actuated by a photodetection arrangement involving the interruption of a beam of light or the detection of irradiated energy within a prescribed bandwidth. The latter mechanism of photodetection is very susceptible to extraneous light. To avoid false operation, the detection system is sensitized to the reflected signal simply by requiring the user or the user's hands to be positioned very close to the light source to function. Also, the pumping sequence and mode of operation requires considerable electrical power to discharge the desired dosage of fluid. Accordingly, such dispensers are, by their nature, large, bulky units which are far more costly than their mechanical counterparts.
The electronic dispenser of the present invention has been designed to operate at very low power, either from a battery with very little power drain or from a conventional AC source of power. The system utilizes a rotary motor integrated in an assembly with a self-priming, self-venting pump and a conventional container for storing the fluid to be dispensed. The motor is controllably actuated by an electronic control circuit which uses a photodetection circuit designed to respond only to a reflected infrared signal of predetermined configuration. By integrating a motor drive with a conventional, mechanically-operated, self-priming pump, the system cost is reduced to a fraction of the cost of the commercially available electronically-controlled fluid dispensers. In addition, by generating a light pulse of predetermined waveshape, controlled detection is simplified without concern of extraneous light. The simplicity of the system is its unique attribute.